docs: def get_lexer_for_filename(_fn, code=None, **options):
      """Get a lexer for a filename.
  
      If multiple lexers match the filename pattern, use ``analyse_text()`` to
      figure out which one is more appropriate.
  
      Raises ClassNotFound if not found.
      """
      res = find_lexer_class_for_filename(_fn, code)
      if not res:
          raise ClassNotFound('no lexer for filename %r found' % _fn)
      return res(**options)